Major issue with witch water

So, I’ve been having quite the problem here. So I’m trying to automate soul sand, but when I do, or try to, my witch water keeps transforming to blood the second witch water hits 1000mb. It’s like instant… for context, the blood generating is from tinkers construct. I do have mobs around but not anywhere near the barrel, or barrels, if anyone knows why this is happening, I’d love to know